An internal combustion engine includes a combustion chamber, where a fuel air mixture is burned to cause movement of a set of reciprocating pistons, and a crankcase, which contains the crankshaft driven by the pistons. During operation, it is normal for the engine to experience “blow-by,” wherein combusted crankcase gases leak past the piston-cylinder gap from the combustion chamber and into the crankcase. These blow-by or crankcase gases contain moisture, acids and other undesired by-products of the combustion process.
It is normal for crankcase gases to also include a very fine oil mist. The oil mist escapes from the engine to the manifold. The oil mist is then carried from the manifold back into the combustion chamber along with the fuel/air mixture. This results in an increase in oil consumption. Additionally the combustion of the oil mist causes a build up of residuals in the combustion chamber and on pistons which over time decreases engine efficiency. An engine typically includes a Positive Crankcase Ventilation (PCV) system for removing harmful gases from the engine and prevents those gases from being expelled into the atmosphere. Accordingly, it is known to incorporate an oil separating device into a PCV system to remove oil from these crankcase gases. The crankcase gases flow through into localized high velocity areas of the oil separator to promote separation of oil from the gases. The oil is re-introduced back to a sump via a drain device which is located generally at the bottom of the oil separator to allow for gravity to assist the drainage of oil. The sump generally holds excess oil in the system.
Though introducing crankcase gases into a localized high velocity area is sufficient to remove large particles of oil from the crankcase gases, micron and sub-micron particles of oil still remain. Oil separating devices such as Punching and Impactor Plates (PIP), or Cyclone Separators may be used to capture small particles of oil, however these oil separating devices are inefficient at capturing sub-micron oil particles. Furthermore, these devices create a high pressure drop which interferes with the drainage of captured oil. Specifically, the high pressure drop across the device interferes with the force of gravity pulling separated oil particles towards the oil drain. Accordingly, it remains desirable to provide an improved oil separator that is more efficient than conventional oil separator designs in removing micron and sub-micron particles of oil from crankcase gases while at the same time assisting gravity in directing oil towards the oil drain.